11784721 has 4 divisors (see below), whose sum is σ = 12691252. Its totient is φ = 10878192.

The previous prime is 11784713. The next prime is 11784727. The reversal of 11784721 is 12748711.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7623121 + 4161600 = 2761^2 + 2040^2 .

It is not a de Polignac number, because 11784721 - 2³ = 11784713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11784727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 453246 + ... + 453271.

It is an arithmetic number, because the mean of its divisors is an integer number (3172813).

Almost surely, 2^11784721 is an apocalyptic number.

It is an amenable number.

11784721 is a deficient number, since it is larger than the sum of its proper divisors (906531).

11784721 is an equidigital number, since it uses as much as digits as its factorization.

11784721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 906530.

The product of its digits is 3136, while the sum is 31.

The square root of 11784721 is about 3432.8881426577. Note that the first 3 decimals coincide. The cubic root of 11784721 is about 227.5655070386.

The spelling of 11784721 in words is "eleven million, seven hundred eighty-four thousand, seven hundred twenty-one".